It is no secret that you should listen to what the players want, and then give it to them.
Yeah this is the main thing.
As a result when I run D&D I've noted three things which just absolutely work for my main group are:
1) NPCs to hate.
This means there need to be NPCs. Dungeons full of non-talking monsters don't work for them. They need NPCs who will talk smack to them and who they can talk smack back to. Usually need multiple tiers of them, too.
2) NPCs to like.
Love would be too strong a word, but if they don't have some positive/helpful NPCs around, they tend to lapse into a sort of cynical attitude towards the world which lowers fun for everyone. This is a bit like the OP's suggestion, but they're not necessarily fan-fans, but just allies and helpers including frenemies, so long as they're transparent about being frenemies.
3) Weird dangerous magic items.
They just really love items which are a total menace. Not boring-as-hell cursed items or the like, but items which do something just really dangerous. Like a large golden needle which tries to mind-control you into stabbing it through your own forehead (at which point it will steal your body). Utterly useless, but they loved it because they could dream of situations where they managed to make one particularly obnoxious NPC or another take it off them.